Good Riddles

Question: When i was 4 my sister was half my age. Now I am 100. How old is my sister now?

Question: What can you feel but never touch, hear but never see?

Question: I rise and fall no matter what, only at finals rest do I not budge, what am I?

Question: I am in everything and in nothing, what am I?

Question: Some people peel my skin some people don't, you eat me nevertheless, with or without, what am I?